Capping unit for closing containers with respective caps

Abstract

Containers ( 2 ) are closed with screw caps ( 3 ) by a unit ( 1 ) of the type comprising a carousel ( 7 ) on which to advance the containers ( 2 ) and the relative caps ( 3 ), driven by a motor ( 6 ) about a respective primary axis ( 5 a ) and equipped with a plurality of capping assemblies ( 11 ) each positioned above a relative container ( 2 ) and capable of movement vertically between a first position, distanced from the container ( 2 ), and a second position of active engagement with the container ( 2 ). Each capping assembly ( 11 ) presents a gripping mechanism ( 17 ) positionable so as to engage a relative cap ( 3 ) when the assembly ( 11 ) is in the second position, and rotatable about a respective secondary axis ( 17 a ) in such a way as to screw the cap ( 3 ) onto a threaded neck ( 4 ) of the relative container ( 2 ). The unit ( 1 ) further comprises first motors ( 14 ) by which the capping assemblies ( 11 ) can be raised and lowered one independently of another, and second motors ( 18 ) by which the gripping mechanisms ( 17 ) can be rotated one independently of another.

1. A capping unit for closing containers ( 2 ) with respective caps ( 3 ), comprising: a carrier and conveyor component ( 5 ) on which to advance the containers ( 2 ) and the respective caps ( 3 ); a motor ( 6 ) associated with the carrier and conveyor component ( 5 ), by which the carrier and conveyor component ( 5 ) is set in rotation about a respective primary axis ( 5   a ); a plurality of capping assemblies ( 11 ) associated with the carrier and conveyor component ( 5 ), each positioned above a corresponding container ( 2 ) and capable of movement vertically between a first position, distanced from the respective container ( 2 ), and a second position actively engaging the container, wherein each capping assembly ( 11 ) presents a gripping mechanism ( 17 ) such as can be associated with a relative cap ( 3 ) when the corresponding capping assembly ( 11 ) is in the second position, and the gripping mechanism ( 17 ) is rotatable in such a way as to screw the cap ( 3 ) onto a threaded neck ( 4 ) of the respective container ( 2 ) about a respective secondary axis ( 17   a ); first drive means ( 14 ) presenting a plurality of primary electric motors ( 14   a ), each one of which associated with a respective capping assembly ( 11 ) by which the single capping assemblies ( 11 ) can be set in motion vertically, one independently of another; second drive means ( 18 ) presenting a plurality of secondary electric motors ( 18   a ), each one of which associated with a respective gripping mechanism ( 17 ) by which the single gripping mechanisms ( 17 ) can be set in rotation one independently of another; and an electronic controller device ( 40 ) connected to each of the primary electric motors ( 14   a ) and the secondary electric motors ( 18   a ); wherein the electronic controller device comprises a processing block ( 41 ) by means of which to vary the operating parameters of each primary electric motor ( 14   a ) and each secondary electric motor ( 18   a ) according to the dimensions of the respective containers ( 2 ). 
     
     
       2. A unit as in  claim 1 , wherein the carrier and conveyor component ( 5 ) comprises:
 a drum ( 8 ) associated with the motor ( 6 ) and rotatable about the primary axis ( 5   a ); 
 a base ( 9 ) associated with the bottom of the drum ( 8 ), on which to stand the containers ( 2 ); 
 a platform ( 10 ), associated with the top of the drum ( 8 ) and facing the base ( 9 ), to which the capping assemblies ( 11 ) are mounted in a circumferential formation. 
 
     
     
       3. A unit as in  claim 2 , wherein each capping assembly ( 11 ) comprises a rod ( 12 ) inserted slidably through a relative guide ( 13 ) afforded by the platform ( 10 ), extending longitudinally in coaxial alignment with the secondary axis ( 17   a ) and presenting a first end ( 12   a ) with which the respective gripping mechanism ( 17 ) is associated, and a second end ( 12   b ) opposite to the first end ( 12   a ). 
     
     
       4. A unit as in  claim 3 , wherein each secondary electric motor ( 18   a ) is mounted between the first end ( 12   a ) of the corresponding rod ( 12 ) and the gripping mechanism ( 17 ) and presents a shaft ( 19 ) rotatable about an axis parallel to the secondary axis ( 17   a ). 
     
     
       5. A unit as in  claim 3 , wherein each primary electric motor ( 14   a ) occupies a position coinciding with the second end ( 12   b ) of the rod ( 12 ) and above the platform ( 10 ). 
     
     
       6. A unit as in  claim 5 , wherein each secondary electric motor ( 18   a ) is mounted between the first end ( 12   a ) of the corresponding rod ( 12 ) and the gripping mechanism ( 17 ) and presents a shaft ( 19 ) rotatable about an axis parallel to the secondary axis ( 17   a ). 
     
     
       7. A unit as in  claim 5 , wherein each primary electric motor ( 14   a ) comprises a shaft ( 15 ) rotatable about a respective axis perpendicular to the secondary axis ( 17   a ), and a gear ( 15   a ) keyed to the shaft ( 15 ). 
     
     
       8. A unit as in  claim 7 , wherein each secondary electric motor ( 18   a ) is mounted between the first end ( 12   a ) of the corresponding rod ( 12 ) and the gripping mechanism ( 17 ) and presents a shaft ( 19 ) rotatable about an axis parallel to the secondary axis ( 17   a ). 
     
     
       9. A unit as in  claim 7 , wherein each rod ( 12 ) presents a rack ( 16 ) extending longitudinally along the respective second end ( 12   b ) and engaged in meshing contact by the gear ( 15   a ) of each primary electric motor ( 14   a ), in such a way that the rod ( 12 ) can be set in motion vertically by rotation of the gear ( 15   a ). 
     
     
       10. A unit as in  claim 9 , wherein each secondary electric motor ( 18   a ) is mounted between the first end ( 12   a ) of the corresponding rod ( 12 ) and the gripping mechanism ( 17 ) and presents a shaft ( 19 ) rotatable about an axis parallel to the secondary axis ( 17   a ). 
     
     
       11. A unit as in  claim 10 , wherein the gripping mechanism ( 17 ) comprises:
 a gripper ( 20 ) attached to the shaft ( 19 ) of the respective secondary electric motor ( 18   a ), capable of movement between an open condition in which the relative capping assembly ( 11 ) is in the first position and a closed condition in which the relative capping assembly ( 11 ) is in the second position with the gripper ( 20 ) engaging the relative cap ( 3 ); 
 an actuator ( 25 ) by which the gripper ( 20 ) is caused to alternate between the open and closed conditions; 
 a transmission component ( 31 ) interposed between the gripper ( 20 ) and the actuator ( 25 ), by which motion is relayed from the actuator ( 25 ) to the gripper ( 20 ). 
 
     
     
       12. A unit as in  claim 11 , wherein the gripper ( 20 ) comprises:
 a carrier element ( 21 ) of substantially cylindrical appearance, associated coaxially with the shaft ( 19 ) of the secondary electric motor ( 18   a ); 
 a plurality of jaws ( 22 ) hinged circumferentially to the cylindrical carrier element ( 21 ) and capable of movement between a position drawn toward one another, corresponding to the closed condition of the gripper ( 20 ), and a position spread apart from one another, corresponding to the open condition of the gripper ( 20 ). 
 
     
     
       13. A unit as in  claim 12 , wherein each jaw ( 22 ) presents a substantially curved appearance and is identifiable as having a first end ( 22   a ) furnished with a following roller ( 23 ), a second end ( 22   b ) opposite to the first end ( 22   a ), furnished with a contact element ( 24 ) designed to engage the cap ( 3 ), and an intermediate portion ( 22   c ) disposed between the first end ( 22   a ) and the second end ( 22   b ) and hinged to carrier element ( 21 ). 
     
     
       14. A unit as in  claim 11 , wherein each transmission component ( 31 ) comprises a plunger ( 32 ) of substantially frustoconical geometry coaxially encircling and slidable along the shaft ( 19 ) of the secondary electric motor ( 18   a ), and a mechanical linkage ( 33 ) coupled rigidly to the plunger ( 32 ). 
     
     
       15. A unit as in  claim 14 , wherein the plunger ( 32 ) presents a downwardly tapering outer surface ( 32   c ), and the following roller ( 23 ) of each jaw ( 22 ) rolls vertically on the downwardly tapering outer surface ( 32   c ). 
     
     
       16. A unit as in  claim 14 , wherein the actuator ( 25 ) is a linear actuator coupled to the mechanical linkage ( 33 ) in such a way as to induce a vertical movement of the plunger ( 32 ).